Method and device for balancing a roll

ABSTRACT

The present invention concerns a method and a device for the balancing of a roll. Fluidizable balancing agent is placed onto a face of the roll at a location required by the balancing, at which the agent adheres and hardens.

This is a division of application Ser. No. 07/682,665, filed Apr. 9,1991, now abandoned which in turn is a continuation of Ser. No.07/370,596, filed June 23, 1989, now U.S. Pat. No. 5,096,738.

BACKGROUND OF THE INVENTION

The invention concerns a method for the balancing of a roll andequipment used in this method.

The balancing of cylinders and rolls in a paper machine has been, as arule, quite questionable. Both in dynamic balancing and in staticbalancing, it must be possible to place the balance weights at locationsas invisible as possible, and so that the weights do not hamperoperation of the device. In static balancing, it is sufficient to placethe weights at the correct distance from the axis of rotation.

To accomplish dynamic balancing, it must also be possible to placebalanced weights at the correct location in the roll in relation to itslength. In such a case, a difficulty encountered is placing the balancedweights so that they do not hamper the operation of the roll. In such acase, usually the only alternative is to be able to place the weightsinside the axle.

In prior art balancing solutions, the arrangements often required acentral support axle or some other support construction, to which thebalance weights can be separately attached. A particular drawback in theprior art solutions is that it has not been possible to fix the balanceweights to the roll mantle face itself, because affixing to this facewas not possible without damaging the inner face of the roll mantle.

Balancing solutions are also known in which liquid has been passed intoseparate filling compartments in the interior of the roll. A drawback ofthis solution is the high cost of construction. It has been necessary toconstruct separate liquid compartments in the interior of the roll topermit balancing.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to overcome thebalancing problems described above and to provide a balancing method andbalancing equipment of an entirely new type, especially for rolls andcylinders in paper machines.

These and other objects are attained by the present invention which isdirected to a method for balancing a roll, comprising the step ofplacing onto a face of the roll, a fluidizable balancing agent at alocation required for balancing, whereby the agent adheres to the rollface and hardens at this location. The present invention is alsodirected to apparatus for balancing a roll, which comprises means fordelivering fluidizable balancing agent to a location required forbalancing the roll on a surface thereof, where the agent adheres andhardens.

In the present invention, the use of a fluidizable mix for balancing hasbeen achieved, this mix hardening to its ultimate hardness after it hasbeen applied to the balancing point or location.

The method in accordance with the present invention is principallycharacterized by a fluidizable balancing agent being placed onto a faceof the roll at a location required by the balancing, at which locationthe agent adheres and hardens.

The equipment in accordance with the present invention is principallycharacterized by comprising means by its which the fluidizable balancingagent can be brought to the balancing point, at which the agent adheresand hardens.

The balancing mix that is used is preferably polyurethane or silicon mixor epoxy resin. It is also possible to use some other substance whichcan strongly adhere to a cleaned cylinder mantle face even with highmaterial thicknesses. The balancing agent is chosen. The bearing in mindthe hardening time must be sufficiently short. Before the balancing mixis placed at the balancing location inside the roll onto its innermantle face, the face is cleaned.

By means of the method of the invention, a balance weight can be placedon the roll mantle at any location whatsoever, between the ends of theroll. In the method of the invention, mechanical components are notrequired. A suitable amount of the balancing agent is applied to thedesired location, and the agent is allowed to dry to the ultimatehardness. The balance weight does not require any separate protectingcovers either.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further described below with reference tocertain advantageous embodiments thereof illustrated in the accompanyingdrawings and to which, however, the present invention is not intended tobe confined. In the drawings,

FIG. 1 is a longitudinal sectional view of a paper machine roll; and

FIG. 2 is a sectional view taken along line A--A in FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 provides a more detailed illustration of the method in accordancewith the present invention, and of the equipment for carrying out thismethod. The roll 10 comprises a roll mantle 11 whose ends are providedwith end flanges 13. The axle journals 14 are connected to the endflanges 13. The flange 13 includes a hole 15 passing through the flange,preferably a cast hole or a bore made afterwards.

A device 17 for application of the balance weight comprises a duct 18,preferably a rigid pipe, through which the balancing agent 19 is passedto the balancing point. The pipe comprises a straight portion 18a and anend portion 18b which is situated at the end of the straight portion 18aand is substantially at an angle of 90° to the straight portion 18a. Thepipe 18 is introduced into the roll 10 through the hole 15. Thebalancing agent is composed of a resilient, elastic, fluidizable mixwhich solidifies to its ultimate hardness only after it has been placedonto the balancing point, e.g. onto an inner face 12 of the roll 10 (inthe direction of arrow L₁).

Before balancing, the inner face 12 of the roll 10 must be carefullycleaned. At the end of the pipe 18, an actuator 20 is fitted by whichthe balancing agent 19 is conveyed to the balancing point. The device 20is preferably composed of a cylinder which has a piston 22 therein. Thebalancing agent is suctioned out of a tank 24 or equivalent and into thespace between the cylinder mantle 23 and the piston 22. When the piston22 is displaced by means of a shaft 21 in the direction L₂, the flow ofthe balancing agent 19 back into a tank 24 is prevented by means of aone-way valve 25.

FIG. 2 is a sectional view taken along line A--A in FIG. 1. When thebalancing is being carried out, the roll 10 is rotated so that thebalancing point becomes positioned at the bottom location in relation tothe rest of the roll mantle. In this way, the desired quantity ofbalancing agent 19 is brought to the desired point. It is permitted toharden before the roll 10 is rotated to the next balancing position,i.e. the roll 10 is rotated only after the agent 19 has hardened, withadditional balancing agent then being conveyed to the new balancinglocation at the lowest position of the roll.

The device 17 comprises a substantially rigid pipe 18 which is turncomprises a substantially straight portion 18a extending from theactuator 20, and at an end thereof, a downwardly-directed portion 18b.By means of this pipe form, the balancing agent 19 can be exactlytransferred to the desired location on the inner face 12 of the rollmantle 11.

A fluid mix is used as the balancing agent 19 which hardens by means ofheat, air, moisture, or other additional components, or which can beseparately hardened to its ultimate hardness only after it has beenapplied to the balancing location. Advantageously, the balancing agent19 is that used in polyurethane or epoxy resin or silicon mix.

After the balancing has been carried out, the holes 15 are preferablyclosed by means of plugs 16. Arrows L₃ denote the application of theplugs 16 into the respective holes 15 after the balancing.

The preceding description of the present invention is merely exemplary,and is not intended to limit the scope thereof in any way.

What is claimed is:
 1. A balanced roll, comprisinga roll comprising amantle having an inner surface, a fluidizable balancing agent disposedat a location on said inner surface necessary for balancing said roll,said agent adhering and hardening while said roll is both stationary andnonrotating, said roll being unbalanced prior to the application of saidfluidizable balancing agent and said roll being balanced uponapplication of said agent.
 2. The balanced roll of claim 1, furthercomprising means for delivering fluidizable balancing agent to saidlocation on said inner surface of said mantle, wherein said meanscomprise a pipe through which the balancing agent is delivered to abalancing location.
 3. The balanced roll of claim 2, wherein said meansadditionally comprise an actuator for conveying the fluidizablebalancing agent through said pipe.
 4. The balanced roll of claim 3,wherein said actuator comprises a cylinder communicating with said pipeand piston within said cylinder, by means of which the fluidizablebalancing agent is pushed through said pipe.
 5. The balanced roll ofclaim 4, wherein said pipe extends into an interior of said roll througha hole provided in a flange situated at an end of the roll mantle. 6.The balanced roll of claim 5, comprising an end bent substantiallyperpendicularly to an adjacent portion of said pipe.
 7. The balancedroll of claim 1, wherein the fluidizable balancing agent is polyurethaneor epoxy resin or silicon mix.